Tesla Solid State Battery: Fact or Fiction?
Tesla is known for its innovation and leadership in the electric vehicle (EV) industry, but one area where it has not made much progress is in developing solid state batteries. Solid state batteries are a type of battery that use a solid electrolyte instead of a liquid one, which could potentially offer higher energy density, faster charging, and better safety than conventional lithium-ion batteries. Many experts and competitors have touted solid state batteries as the next big thing in EVs, but Tesla has remained skeptical and focused on improving its own lithium-ion technology.
In this blog post, we will explore the current state of solid state battery research and development, and compare it with Tesla's latest battery breakthrough: the 4680 cell. We will also discuss the challenges and opportunities that solid state batteries present for Tesla and the EV industry as a whole.
What are solid state batteries and why are they important?
Solid state batteries are batteries that replace the liquid or gel-like electrolyte in conventional batteries with a solid material, such as a ceramic, polymer, or glass. The electrolyte is the medium that allows ions to flow between the positive and negative electrodes of a battery, enabling the chemical reactions that produce electricity.
By using a solid electrolyte, solid state batteries could potentially overcome some of the limitations of liquid electrolytes, such as:
- Low energy density: Liquid electrolytes take up space and add weight to the battery, reducing the amount of energy that can be stored per unit volume or mass. Solid electrolytes could enable thinner and lighter batteries with more capacity.
- Slow charging: Liquid electrolytes limit the rate at which ions can move between the electrodes, resulting in longer charging times. Solid electrolytes could allow faster ion transport and higher power output, enabling quicker charging.
- Safety risks: Liquid electrolytes are flammable and can leak or catch fire if the battery is damaged or overheated. Solid electrolytes are more stable and less prone to thermal runaway, reducing the risk of fire or explosion.
Solid state batteries have been in development for over 40 years, but have not yet reached commercial viability due to various technical challenges, such as:
- Scalability: Solid electrolytes are difficult to manufacture at large scale and low cost, especially for complex shapes and sizes. They also require precise alignment and contact between the electrodes and the electrolyte, which can be challenging to achieve consistently.
- Performance: Solid electrolytes often have lower conductivity and higher resistance than liquid electrolytes, which can reduce the efficiency and lifespan of the battery. They also tend to degrade over time and cycles, especially at high temperatures and voltages.
- Compatibility: Solid electrolytes may not be compatible with existing electrode materials or battery architectures, requiring new designs and materials that may not be readily available or proven.
Despite these challenges, many companies and researchers are working on developing solid state batteries for various applications, including EVs. Some of the notable players in this field include:
- Toyota: The Japanese automaker has been investing in solid state battery research for over a decade, and claims to have achieved a breakthrough in 2020 that could enable mass production by 2025. Toyota plans to unveil a prototype EV powered by solid state batteries at the 2020 Tokyo Olympics.
- QuantumScape: The US-based startup, backed by Volkswagen and Bill Gates, has been developing solid state batteries based on a ceramic electrolyte since 2010. QuantumScape claims to have achieved an energy density of over 400 Wh/kg (compared to about 250 Wh/kg for current lithium-ion batteries), as well as fast charging capability (80% charge in 15 minutes) and long cycle life (over 800 cycles). QuantumScape aims to start production by 2024 in partnership with Volkswagen.
- ProLogium: The Taiwanese company has been developing solid state batteries based on a flexible ceramic-polymer composite electrolyte since 2006. ProLogium claims to have achieved an energy density of over 500 Wh/kg, as well as high power density (over 10 kW/kg) and safety (no fire or explosion even when punctured or cut). ProLogium has partnered with Mercedes-Benz to develop solid state batteries for EVs by 2025.
How does Tesla's 4680 cell compare with solid state batteries?
Tesla's 4680 cell is not a solid state battery, but rather an improved version of its existing lithium-ion technology. The 4680 cell was unveiled by Tesla at its Battery Day event in September 2020, where it announced its ambitious plan to achieve terawatt-hour scale battery production by 2030.
The 4680 cell is named after its dimensions: 46 mm in diameter and 80 mm in height. It is significantly larger than Tesla's previous cells (such as the 2170 used in the Model 3 and Model Y), which allows it to pack more energy and power in a smaller space. Tesla claims that the 4680 cell can achieve a 16% increase in range, a 14% reduction in cost, and a 5x increase in power compared to its previous cells.
The 4680 cell also features several innovations that enhance its performance and efficiency, such as:
- Tabless design: The 4680 cell eliminates the metal tabs that connect the electrodes to the external terminals of the battery, which reduces the electrical resistance and thermal stress of the cell. Instead, the electrodes are laser-patterned with shingled spirals that enable direct contact between the current collectors and the terminals, resulting in faster charging and lower heat generation.
- Dry electrode coating: The 4680 cell uses a dry process to coat the electrode materials onto the current collectors, which eliminates the need for solvents and drying ovens that are used in conventional wet processes. This reduces the capital and operating costs of battery manufacturing, as well as the environmental impact of solvent disposal.
- Silicon anode: The 4680 cell incorporates silicon as an additive to the graphite anode, which increases the capacity of the anode by allowing more lithium ions to be stored. Silicon has a much higher theoretical capacity than graphite (about 10 times), but it also expands and contracts significantly during charging and discharging, which can cause cracking and degradation of the anode. Tesla claims to have solved this problem by using a raw metallurgical-grade silicon that is stabilized with an elastic polymer coating.
- Nickel-cobalt-aluminum (NCA) cathode: The 4680 cell uses a high-nickel NCA cathode, which has a higher energy density and lower cost than other cathode materials, such as nickel-manganese-cobalt (NMC) or lithium-iron-phosphate (LFP). Tesla also plans to reduce the cobalt content of its cathode to near-zero, as cobalt is expensive and has ethical and environmental issues associated with its mining. Tesla also aims to source its nickel and other metals locally and sustainably, as well as recycle its batteries at the end of their life.
Tesla's 4680 cell is expected to be used in its upcoming vehicles, such as the Cybertruck, Semi, Roadster, and Model Y made in Berlin and Texas. Tesla is currently ramping up its pilot production of the 4680 cell at its Fremont factory, and plans to reach mass production by 2022.
Tesla's 4680 cell is not directly comparable with solid state batteries, as they use different technologies and have different advantages and disadvantages. However, based on the available information, we can make some rough estimates of how they stack up against each other in terms of key metrics, such as:
- Energy density: Solid state batteries claim to have higher energy density than Tesla's 4680 cell, ranging from 400 Wh/kg to 500 Wh/kg, compared to about 300 Wh/kg for the 4680 cell. However, these figures are based on laboratory tests or projections, and may not reflect the actual performance in real-world conditions or mass production. Tesla's 4680 cell has been demonstrated in prototype vehicles and is closer to commercialization than solid state batteries.
- Charging speed: Solid state batteries claim to have faster charging speed than Tesla's 4680 cell, ranging from 15 minutes to 80% charge for QuantumScape's battery to less than 10 minutes for ProLogium's battery, compared to about 20 minutes for Tesla's Supercharger V3 (250 kW). However, these figures are also based on laboratory tests or projections, and may not account for factors such as temperature, voltage, power output, or battery degradation. Tesla's Supercharger network is already widely deployed and compatible with its vehicles, while solid state batteries may require new charging infrastructure and standards.
- Safety: Solid state batteries claim to have better safety than Tesla's 4680 cell, as they are less likely to catch fire or explode due to their stable solid electrolyte. However, solid state batteries may still face other safety issues, such as dendrite formation (metallic growths that can pierce through the electrolyte and cause short circuits), thermal runaway (uncontrolled heating that can damage the battery or cause fire), or mechanical stress (cracking or delamination of the electrolyte or electrodes due to expansion or contraction). Tesla's 4680 cell has been designed with safety features such as thermal management systems, firewalls, and fuses that can prevent or mitigate these risks.
What are the challenges and opportunities for Tesla and the EV industry?
Tesla is one of the most innovative and influential companies in the electric vehicle (EV) industry. It has revolutionized the automotive market with its cutting-edge technology, sleek design, and visionary leadership. However, Tesla also faces many challenges and uncertainties in its quest to achieve its ambitious goals and maintain its competitive edge. In this blog post, we will explore some of the major challenges and opportunities for Tesla and the EV industry as a whole.
Challenges:
- Competition: Tesla is not the only player in the EV market. Many established automakers, such as Volkswagen, Toyota, Ford, and Hyundai, are investing heavily in developing and launching their own EV models. Some of them have already surpassed Tesla in terms of sales volume or market share in certain regions or segments. Moreover, Tesla also faces competition from new entrants, such as Rivian, Lucid, and Nio, that are targeting niche markets or offering premium features. Tesla will have to constantly innovate and differentiate itself from its rivals to retain its loyal customers and attract new ones.
- Supply chain: Tesla relies on a complex and global supply chain to source its raw materials, components, and batteries. However, this also exposes it to various risks and uncertainties, such as fluctuations in prices, availability, quality, and regulations. For instance, Tesla has faced challenges in securing enough lithium-ion cells for its battery packs, which are essential for its EV production and performance. Tesla has also faced disruptions in its supply chain due to the COVID-19 pandemic, natural disasters, trade wars, and labor issues. Tesla will have to optimize its supply chain management and diversify its sources to ensure its operational efficiency and resilience.
- Regulation: Tesla operates in a highly regulated industry that is subject to various laws and standards regarding safety, emissions, consumer protection, taxation, and incentives. These regulations vary across different countries and regions, and can change over time depending on the political and social climate. For example, Tesla has faced regulatory hurdles in some of its key markets, such as China, Germany, and India, that have affected its sales or expansion plans. Tesla has also faced legal disputes with some of its competitors or stakeholders over issues such as patents, trademarks, subsidies, or labor rights. Tesla will have to comply with the existing and emerging regulations and engage with the relevant authorities and parties to protect its interests and reputation.
- Profitability: Tesla has achieved remarkable growth and success in terms of revenue, market capitalization, and innovation. However, it has also struggled to achieve consistent profitability and positive cash flow. Tesla has incurred significant losses and debts over the years due to its heavy investments in research and development, production capacity, infrastructure, marketing, and acquisitions. Tesla has also faced challenges in scaling up its production and delivery to meet the growing demand for its EVs. Tesla will have to improve its financial performance and stability to sustain its growth and expansion.
Opportunities:
- Demand: The demand for EVs is expected to grow rapidly in the coming years due to various factors such as environmental awareness, technological advancement, cost reduction, consumer preference, and policy support. According to some estimates, the global EV market could reach $803 billion by 2027, with a compound annual growth rate of 22.6%. Tesla has a strong brand recognition and customer loyalty that gives it an advantage in capturing this growing demand. Tesla also has a diversified product portfolio that caters to different segments and needs of the EV market. Tesla will have to continue to offer high-quality products that meet or exceed the expectations of its customers.
- Innovation: Tesla is widely regarded as a leader and pioneer in innovation in the EV industry. It has developed some of the most advanced technologies and features for its EVs, such as autonomous driving, over-the-air updates, supercharging network,